Continuous carbonizing furnace



July 17, 192s. y 1,617,136

' W. M. HEPBURN CONTINUOUS CARBONIZING FURNACE Filed Feb. 15, 1926 nmsmhm @3M-M3 @Mime/n Patented `vluly 17, 1928,

UNITED STATES PATENT OFFICE.

WILLIAM I. HEPBURN, AOF DENVER, COLORADO, ASSIGNOB EllO SURFACE COHBUSTION COMPANY, -A CORPORATION OF NEW YOK. J

CONTINUOUS CARBONIZING` FURNACE.

Applicationiled February 1-5, 1926. Serial No. 88,197.

This invention relates to improvements in furnaces andmore particularly to a furnace `in which material may be carbonized while being moved through the furnace from one end to the other thereof.

In carbonizii'ig furnaces it is of primary importance to secure uniform temperatures and to control the character of the atmosphere surrounding the work to be carbonized so as to'prevent oxidation of the work or material to b e treated. It has been found that oxidation ofthe material does not begin until the work. is at a comparatively high temperature, for. example, at a temperature of about 1300O F. and over. The present invention aims to take advantage of this fact by constructing acarbonizing furnace which shall have two distinct heating chambers, one ofwhich chambers shall be open at the top to permit the circulation of burned gases over the work whereby the work to be carbonized may be quickly heated f preparatory -to its introduction into the high temperature soakingk zone, and the other chamber being of the muille type wherein the work maybe maintained at a carbonizingr' temperature in a V:substantially dead atmosphere, the muflie constituting the soaking zone.v A

In accordance with the present invention the heating chamber into which the work to be carbonized is first introduced comprises an open top tunnel or heating chamber having a relatively thin floor beneath which fuel is burned and having relatively thin side walls between which and ythe walls of the furnace `the combusted gases formed by the burning of the `fuel beneath the floor pass upwardly' for circulation about the work before passing out ofthe furnace.v The soaking zone or chamber differs primaril from the preliminary heating chamber by aving ka roof in spaced relation to the roof of the furnace whereby the -hot gases passing upwardly along the outer ,sides of the chamber will be prevented from coming into contact with the work. The combustion chamber beneath the soakingchamber or inutile is independent of the combustion chamber below the preliminary `heating' chamber, a wall separating them. f The combusted gases leave the furnace through openings in its roof near the charging end ofthe furnace. By causing the gases to leave near the charging end of the furnace any tendency of the gases to the furnace at the same time.

enter the muflle is eiectually prevented with A the result that the atmosphere within the muflie is substantially a dead atmosphere.

For a fuller understanding of the invention reference is made to the detailed delshowing the furnace as provided with a recuperator above the openings through which the gases pass out of the furnace and also showing a conventional type of means for pushing the work into the furnace;

Fig. 2 is a transverse section taken on line 2-2 of Fig. 1 and showing the preferred manner of constructing the preliminary heating chamber, and

Fig. 3 is a transverse sectional view taken on line 3 3 of Fig. 1 and showing the manner of constructing the inutile.

The base of the furnace is indicated at 10 and may be of any suitable construction as may also its side walls 12 and top 14. The door through which the work to be carbonized is introduced into the furnace is indicated at 16 and the exit door at 18, these doors being suspended in any suitable manner. In front of the charging door is a.

bench 20 on which is arranged a suitable` pusher enerally indicated at 22 for pushing the wor to be carbonized into the furnace. The work will. usually be placed in boxes (not shown). Extending through the furnace are paralleltracks 24 so arranged that two rows of boxes may be pushed through These trac s are suitably supported in spaced relation to the base 10 of the furnace and the space between the tracks is bridged by relatively thin Hoor sections 26` shown as of arched form. A series of races 28 between the tracks serve to give rigidity tothe structure.

The interior of the furnace is divided into two distinct heating chambers, a preliminary heating chamber having a heating trough, the heating chamberas a whole being generally indicated by letter A and a soaking chamber or mule enerally indicated by letter B. Both of t ese chambers have side walls 30 extending upwardly in spaced relation with respect to.. the walls 12 of the 60 scription thereof taken in connection with y burners are of a type to burn fuel cil. However, the improved furnace is equally well adapted to burn gas.

The central pier or support on which the central track is supported is provided with transversely extending openings 40 to permit free circulation of the burning gases`beneath the floor of the furnace. The combusted gases pass from the combustion chambers through a plurality of lateral ports 42 in the supports on which the side tracks 24 rest and pass upwardly into the space 44 between the chamber side walls 30 and the furnace walls l2.

In the case of the preliminary heating chamber A, there is provided between the side walls 30 and the adjacent furnace walls a series of abutnients 46 against which the upper ends of the side walls 30 rest. The space between adjacent; ends of these abutinents 46 form passages 48 through which the combusted gases must pass. The effective size of these passages may be controlled by shiftable blocks 50, only one of which is shown in Fig. 1. By regulating the size of the passages 48 the circulation of the combusted gases may be controlled so as to obtain a uniform temperature throughout the length of the heating chamber A.

Extending downwardly from the abutments 46 are additional supports 46"for the chamber walls 30 and these supports are preferably provided with openings 52 through which the combusted gases may ow, as for example, when certain of the passages 48 are closed by the shiftable members 50. The coinbusted gases after passing through the passages 48 between the abutments 46 will be detiected downwardly from the arched roof 54 of the furnace and thereby caused to circulate Within the tunnel por# tion ofthe chamber A and around the work therein before passing out of the chamber. The gases pass out of the furnace through a row of openings 56 arranged in the roof 54 thereof adjacent the charging end of the furnace as clearly indicated in Fig. l. In order to utilize the residual heat contained in the gases they are passed through a recuperator 58 of any approved form, said recuperator being arranged on the top of the furnace in alinement with the openings 56 in the roof thereof.

Referring now to the soaking chamber B,

the combusted gases after entering the space 44 between the side walls 30 of the chamber and the adjacent walls of the furnace are. caused to travel 'lengthwise of the walls by reason of the fact that a continuous wall support 60 is provided between the top of each wall and the adjacent wall of the furnace. These gases tlow toward the far end of the furnace and pass upwardly through a passage 62 adjacent the end of the chamber from whence they circulate over the roof 32 of the chamber and flow toward the. charging' end of the furnace and ont through the openings 56 in the rootI al thereof as previously described in connection with the preliminary heating chamber At. Vhile the heating chamber B is in elleet, a continuation of the heating chamber A exA cept for the fact that the heating chamber B has a roof 32 whereby the chamber l constitutes a muilie, there is no tendency for the conibusted gases to enter the mnflle l by reason of the fact that the combusted gases formed beneath the inutile B are caused to travel toward the charging end of the furnace on their way out of the same. The result is that the atmosphere within the muiie B is substantially a dead atmosphere in which the work may be heated or soaked without coming in contact with the flow of the combusted gases.

By providing separate combustion cham bers for the respective heating chambers A and B the temperature of each chamber may be etfectually controlled. It will be noted that the work which enters the chamber A is heated by heat radiating from the floor and side walls thereof and by the circulation of Vthe combusted gases within the tunnel of the chamber whereas in the inutile chamber B all of the heating is by radiation of heat from the floor, side walls and roof of the chamber. After the work has been soaked for the requisite period the door 18 is opened and the boxes rolled out of the furnace as on rollers 64 mounted von a suitable bench at the exit end of the furnace.

A carbonizing furnace constructed in accordance with the present invention satisfactorily meets all the requirements of earbonizing furnaces and may be operated at less fuel cost and constructed at consider'- ably less expense than furnaces of the continuous muie type. As already indicated. oxidation of thel work ldoes not occur until a relatively high temperature has been reached and this fact has been taken advantage of by constructing the furnace in sepaL rate heating sections. one section of which is an open top tunnel whereby the com busted gases may How around the work and the other of which is a tunnel which protects the work from direct contact with the combusted gases. Various changes in details of construction may be made without departing from the spirit of the invention.

What is claimed is.: 1. In ,a furnace, the combination of a mulile, an open top heating chamber having heat permeable walls, the floor and Walls of said chamber forming a continuation of the floor and side Walls of the mufile, a combustion chamber formed beneath the floor of said chamber, ports through which the hot gases from the combustion chamber may pass upwardly exteriorly of the walls of said heating chamber to heat the same, means permitting hot gases to circulate around the inutile, the furnace at a point remote from the mufIle having openings through which the spent gases may pass out of the furnace.

2. In a furnace, the combination of a muiiie, an open top heating chamber having heat permeable walls, the ioor and walls of said chamber forming a continuation of the floor and side walls of the muflie, a combustion chamber formed beneath the floor vof said chamber, ports through which the hot gases from the combustion chamber may pass upwardly exteriorly of the walls of said heating chamber to heat the same, means permitting hot gases to circulate around the mulile, the furnace at a point remote from the muiiieA having openings through which the spent gases may pass out of the furnace,

and means for controlling the flow of the hot gases through the ports associated With said heat-ing chamber. 1

3. In a furnace, the combination of a mufHe, an open top heating chamber having heat permeable Walls, the lfloor and walls of said chamber` forming a continuation 0f the floor andy side walls of the muiile, a combustion chamber formed beneath thek floor of 'said chamber, ports through which the hot gases from the `combustion chamber may pass upwardly exteriorly of the Walls of said heating chamber to heat the same, .a combustion chamber beneath' the fioor of said inutile,

means for directing the flow of the hot gases from the last mentioned combustlon chamber f exterior-ly of the side Walls of the muiile and towards that end of the mufle remote from the heating chamber, the furnace at a point remote from the ,muile havingy openings through Wliichtlie spentv gases may pass out of the furnace. n

v4. In a furnace, the combination of a pair of heating chambers having their floor and side walls supported in spaced relation with respect to the floor and side walls of the furnace. the space beneath the floor of the respective chamber; constituting independent' combustion chambers in which fluid fuel may be burned, said furnace having an outlet for the products of combustion adjacent one end of the furnace, that heating chamber the more remote from said outlet having a roof in spacedV relation to the roof of the furnace,

and means permitting the .products of combustion formed by the burning of fuel in said combustion chambers to flow upwardly between the side Walls of the heating chambers and the side walls of the furnace.

5.l In a furnace, the combination of a pair of heating chambers having their floor and side walls supported in spaced relation with respect to the floor and side walls of the furnace, the floor of said chambers constituting chamber, and means a lsociated with the last' named chamber for causing the gases to flow toward the :far end thereof along its outer' side walls before passing out of the furnace.

6. In a furnace, the combination of aj muffle and an open top heating chamber, lthe Inuiiie being supported in spaced relation with respect to the interior walls, roof and floor ofthe furnace and the side walls and floor of the heating chamber being in spaced relation with respect to the walls and floor of the furnace, mutually independent com- 1`bustion chambers beneath the floor of the muftle and heating chamber, means for introducing fluid fuel into said combustion chambers, passa-ges as ociated with the `exteriorside walls of said mulle through which the products of combustion formed in said combustion chambers may pass from the latter toward the end of the mule :remote from the heating chamber, passagesin the furnace roof adjacent the entrance to said heating chamber through which the products of combustion from both combustion chambersmay pass Iout of the furnace, and means associated with the side walls of the heating chamber for controlling the flow of products of combustion from the combustion chamber associated with the bottom of said trough, and means for ind'ucing the spent heating gases t0 flow -in a directlon 'away from said heating chamber and out of the furnace chamber.

ing gases to the trough and exteriorly of the side Walls thereof, and means 'for indnc ing the spent heating gases to low in a direction away l'roln the heating chambei` and out of the furnace chamber.

i). Inv a carbonizing furnace. the combination of a healing chamber, a heating trough commuuu-atingr with one end thereof, means l'or surrouinling said trough with heating ga es. and means or inducing said heating gases to tlow in a. direction away from said healingr chamber.

10. In a rarbonizing furnace, the combi nation ot' a heating chamber, means lfor heating said chamber, a heating trough communicating with one end ot' said chamber,

means for completely surrounding said trough with heating gases, and means for inducing said heating gases to flow in a direction away from said heating chamber.

ll. A furnace as claimed in claim l, characterized by the 'fact that said point from which the products of combustion escape is in the root ol the furnace.

1Q. ln a furnace, the combination of a mulle, an open top heating chamber having: heat permeable walls, the -floor and walls of .said chamber forming a continuation of the floor and side walls ol the mullle, a combustion chamber formed beneath the floor of said chamber` ports through which the hot. gases l'rom the combustion chamber may pass upwardly cxteriorly of the walls of said heating chamber to heat the same, and means` permitting hot gase; to circulate around the mnlle.

In testimony,v whereof I aix my signature.

WILLIAM M. HEPBURN. 

